"Now, California issues like protecting the environment, growth, traffic, water will be important," he predicted.

California's new clout is not assured. By rescheduling to Feb. 5 from June, California joins what McCain strategist John Weaver calls an emerging "national primary" — a day when as many as 19 states could hold presidential contests.

The cluster of Feb. 5 states could eventually include New York, Florida, Illinois and New Jersey, diluting what could otherwise be the impact of a standalone contest. Still, it brings California's rich prize of delegates much closer to the front, where it most counts, and the candidates are reaching out for it.

You'd have to go back to 1972 to find a presidential primary with make-or-break drama in California, says political scientist John Pitney of California's Claremont McKenna College. That year, Democrat George McGovern defeated former Vice President Hubert Humphrey, tightening his grip on the Democratic nomination.